As an aside, the Chrome cookies database on Windows is protected using the Windows Data Protection API[1], which ties encryption keys to a specific user. In the case of the Chrome cookie database, each cookie's payload/value is encrypted using a cryptographic key generated by the DPAPI which is only accessible to that Windows user. Of course, (and as is the case with most situations like this), this does absolutely nothing to protect users against malicious or intrusive programs running with the permissions of that user.
So yeah, you're right. App sandboxing please.